Amazon ECS¶

EC2 Launch Type¶

• ECS stands for Elastic Container Service
• When you launch an docker containers on AWS - launch ECS Tasks on ECS Clusters
• EC2 Launch Type: you must provision & maintain the infrastructure (the EC2 instances)
• Each EC2 instance must run the ECS agent to register in the ECS cluster
• AWS takes care of starting / stopping the containers

Fargate Launch Type¶

• Launch Docker containers on AWS
• You do not provision the infrastructure (no EC2 instances to manage)
• It's all serverless
• You just creeate task definitions
• AWS just runs ECS tasks for you based on the CPU/RAM you need

IAM Roles for ECS¶

• EC2 Instance Profile (EC2 Launch Profile Only)
  • Used by the ECS agent
  • Makes API calls to ECS service
  • Send container logs to CloudWatch Logs
  • Pull Docker image from ECR
  • Reference sensitive data in Secrets Manager or SSM Parameter Store
• ECS Task Role
  • Allows each task to have a specific role
  • Use different roles for the different ECS Services you run
  • Task role is defined in the task definition

Load Balancer Integrations¶

• Application Load Balancer - supported and works for most use cases.
• Network Load Balancer - recommended only for high throughput / high performance use cases, or to pair it with AWS Private Link
• Elastic Load balancer - supported but not recommended (no advanced features - no Fargate).

Data Volumes (EFS)¶

• Mount EFS file systems onto ECS tasks
• Works for both EC2 and Fargate launch types
• Tasks running in any AZ will share the same data in the EFS file system
• Fargate + EFS = serverless
• Use cases: persistent multi-AZ shared storeage for containers
• Note:
  • FSx for Lustre & Windows not supported
  • Amazon S3 cannot be mounted as a file system